---
title: "Load a preview of an s3 file on-behalf of the app author (deployed app)"
method: GET
path: "/w/{workspace}/apps_u/load_file_preview/{path}"
tags: ["app"]
---

# Load a preview of an s3 file on-behalf of the app author (deployed app)

`GET /w/{workspace}/apps_u/load_file_preview/{path}`

## Path parameters

- `workspace` string, required
- `path` string, required

## Query parameters

- `file_key` string, required
- `file_size_in_bytes` integer
- `file_mime_type` string
- `csv_separator` string
- `csv_has_header` boolean
- `read_bytes_from` integer, required
- `read_bytes_length` integer, required
- `storage` string
- `sig` string
- `exp` string

## Response `200`

FilePreview

- WindmillFilePreview
  - `msg` string
  - `content` string
  - `content_type` 'RawText' | 'Csv' | 'Parquet' | 'Unknown', required

## Changes

- **2026-07-16** `d871cf918be2` — 2 info
  - added the new optional `query` request parameter `exp`
  - added the new optional `query` request parameter `sig`
- **2026-07-11** `db86cc12c8a9` — 1 info
  - endpoint added

[Change history](https://skmtc.dev/windmill/apis/windmill-api/changes/w/:workspace/apps_u/load_file_preview/:path/get.md)

---

[API](https://skmtc.dev/windmill/apis/windmill-api.md) · [All operations](https://skmtc.dev/windmill/apis/windmill-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/windmill/windmill-api/revisions/7b281701c340/schema)